NPWS tried to protect the nest by not revealing it was in the river, saying it was “near Georges River”.

A post on the Georges River Wildlife Facebook page on Sunday, read: “It really has been a sad experience both Friday and this morning watching people have fun destroying the Osprey nest and even more so watching the male start nest building efforts again”.

“He seemed obviously exhausted, struggling to break off much smaller branches than what I have seen previously,” she said.

“During most of the nest construction it was winter with much less traffic on the water.

“So, today when he does find a branch and break it off, he usually has to circle around before being able to deliver it to the nest.”

“Whether there were eggs or chicks in the nest, I do not know but whatever was there is floating down the river.

“I suspect the female knows all is lost as she left the nest (not scared off, just left) about 8.10am and had not returned around 12.20pm when I headed home.

“Recently, she only leaves for around 30 minutes to eat then returns, nudging the male off the nest.”

The post said Water Police had visited the site and taken photos.

In September, NPWS regional manager Gary Dunnett said the sighting was “great news for the species as they are not known to breed this far south and may indicate they are repopulating a greater area of their range”

“The Eastern Osprey is quite magnificent to see in flight but despite a wingspan of up to 1.7 metres, they are still much smaller than the White bellied sea eagle," he said.

“The species is uncommon to rare or absent from closely settled parts of south-eastern Australia so for this part of Sydney to have a breeding pair in the area is really very special.

“The fact that an apex predator such as Ospreys are nesting is also a great sign about the environmental health of the Georges River system.

“These birds favour coastal areas where they hunt for fish to feed their growing brood.

“It was not possible to see the number of chicks these birds are tending but they usually incubate 2-4 eggs.

“I am looking forward to seeing the chicks fledge in a month or so and hope they too stay in the area when they fly the nest.”